Method of making fluorinated carbonyl compounds



United States Patent Ofiice Patented May 23, 1967 3,321,515 METHUD OFMAKING FLUORINATED CARBQNYL COMPOUNDS Earl Phillip Moore and Alwin S.Milian, Wilmington,

Del., assignors to E. I. du Pont de Nemours and Company, Wilmington,Del., a corporation of Delaware No Drawing. Filed Apr. 24, 1963, Ser.No. 275,231

10 Claims. (Cl. 260-544) This invention relates to a novel synthesis offluorinated organic carbonyl compounds, and more particularly to thecatalytic rearrangement of fluoroolefin epoxides to yield fluorinatedorganic ketones and acid fluorides.

Recently, methods have been discovered for the economical synthesis offluorocarbon epoxides. In particular, an extremely wide variety offluorocarbon epoxides may be made from the correspondingperfluoroolefins having at least three carbon atoms by the action ofwherein R R and R are fluorine radicals, perfluoroalkyl radicals havingfrom 1 to 8 carbon atoms, omegahydroperfiuoroalkyl radicals having from1 to 8 carbon atoms and, pairwise, perfluoroalkylene biradicals havingfrom 2 to 8 carbon atoms, with a catalytic amount of a catalyst whichmay be an acidic metal oxide, a chloride, bromide or iodide of apolyvalent metal having a valence less than the maximum coordinationnumber, a transition metal carbonyl, or a compound which producesfluoride ions in the reaction medium, such as a tertiary amine, atertiary amine oxide, or a tertiary amide, and thereafter recovering acarbonyl compound from the reaction product.

The catalysts effective for the process of this invention may beclassified as Lewis acids or Lewis bases. In this connection, a Lewisacid denotes a molecule or ion which is capable of accepting an electronpair from another molecule or ion which is thus a Lewis base.

The rearrangement reaction induced by the acidic catalysts evidentlydiffers in mechanism from that induced by Lewis bases. In most cases,this is immaterial. However, in the special case of the epoxides of thel-olefins, the stronger Lewis acids rearrange the epoxide substantiallyexclusively to the trifluoromethyl ketone, whereas the Lewis basesrearrange the epoxide to the isomeric acid fluoride.

The acidic catalysts which are eflective in the process of thisinvention are:

(l) Acidic metal oxides such as A1 TiO W0 and the like of whichgamma-alumina is a preferred catalyst;

(2) Chlorides, bromides, and iodides and oxyhalides of polyvalent metalshaving a valence less than the maximum coordination number, Examples ofsuch halides are A1Cl AlBr SnCl VoCl TiCl Fecl CuCl ZrOCl and the like,of which aluminum trichloride is perferred;

(3) Transition metal carbonyls such as tungsten carbonyl and ironcarbonyl;

With regard to the basic catalysts which may be employed, these may beclassified:

(4) Fluorine compounds having an ionizable fluorine atom including thealkali metal fluorides and acid fluorides such as KF, KHF and CsF, whichis preferred, PF SP and the like. The fluoride ion appears to be theeffective catalyst in these compounds and even compounds which mightotherwise be regarded as Lewis acids, but which, nevertheless, arecapable of yielding fluoride ions, act as bases in this context. Thus BFetherate acts as a weakly basic catalyst in the process of thisinvention. Other alkaline materials which are capable of reacting withthe epoxide reactant to yield intermediates having ionizable fluorineare also found to be effective in promoting the rearrangement in thisinvention. Examples of such compounds are the alkali metal carbonates,the hydroxides of the alkali and alkaline earth metals and the reducedoxides of transition metals;

(5) Tertiary amines, including tertiary aliphatic amines, tertiaryaromatic amines, and heterocyclic compounds having a tertiary nitrogenatom in an aromatic ring system. Included in this group istrimethylamine, triethylamine, dimethylaniline, pyridine and the like;

(6) Amine oxides such as pyridine N-oxide, trimethylamine l -oxide andthe like; and

(7) Tertiary amides such as dimethylformamide, dimethylacetamide,diethylbenzamide and the like.

The rearrangement reaction requires the formation of a carbonyl group atone carbon atom of the epoxide ring accompanied by the migration of afluorine atom to the other carbon atom. Thus, it is essential that atleast one fluorine atom be attached directly to a carbon atom of theepoxide ring.

The perfluoroolefin epoxides may be broadly classified according towhether 1, 2, or 3 of the 4 fluorine atoms are substituted by afluorocarbon radical.

This invention also embraces the case of unsubstituted perfluoroethyleneepoxide which rearranges with great ease in the presence of either acidor basic catalysts to give perfluoroacetyl fluoride.

Monosubstituted perfluoroethylene epoxides rearrange to give an acidfluoride with basic catalysts or to a perfluoromethyl ketone with acidiccatalysts.

or base Ri -C5170 F Rf R CO CFgRr RQCF COR In the case of aperfluoroethylene oxide disubstituted at a single carbon atom, theproduct of rearrangement by the process of this invention is an acidfluoride.

R; Acid R1,

or Base /C@CF; /CFCFO Rt; 0 R1,

In the case of trisubstituted perfluoroethylene epoxides, the productresulting from the rearrangement of this invention is a ketone.

In the above formulae, the radicals R R R and R are perfluoroalkyl oromega-hydroperfluoroalkyl radical containing from 1 to 8 carbon atoms.Specifically included in this definition are branched periiuoroalkylradicals and omega-hydroperfluoroalkyl radicals, and perfluoroalkylradicals containing cyclic groups. In addition to the aforegoiug Rf Rand R may represent one end of a fluoroalkyl biradical, i.e., therearrangement reaction of this invention is applicable to cycliccompounds containing an epoxide ring fused to the cyclic group and tocyclic compounds in which the epoxide ring is in spire-cyclicconformation with a cyclic group.

Various means for contacting the fluorocarbon epoxides with thecatalysts may be employed. The reaction may be performed by contactingthe gaseous fluorocarbon epoxide with the catalyst in suitable cases.The catalysts may also be contacted with the epoxide in the liquidstate, either pure or in the presence of chemically inert solvent ordiluents. In this context, the expression chemically inert refers to adiluent which does not react with the reactant epoxide, with theresultant carbonyl compound, or with the catalyst. For use in the liquidphase, solvents are preferably polar liquids. These include liquidsulfur dioxide, alkyl sulfones, ethers such as dimethyl, ether, diethylether, methyl isop-ropyl ether, dioxane and furane, ethylene glycolethers, and the like, ketones such as acetone, methylethyl ketone,methylisopropyl ketone, and the like, and nitriles such as methylcyanide, ethyl cyanide, and benzonitrile. The above classification ismerely an indication of suitable solvents and is by no means exhaustive.Hydrocarbons including olefins, or liquid fluorocarbons including theperfluoroolefins, may be present as liquid diluents. While theperfluoroolefins are not preferred solvents which tend to promote thereaction, it will be observed that the common method of preparation ofthe epoxides is by epoxidation of the corresponding olefins. Thus, it isby no means essential that an epoxide be purified from the residualparent olefin prior to conversion of the epoxide to the isomericcarbonyl compound by the process of this invention.

When the epoxide is contacted with the catalyst in the gas phase,similar, chemically inert, gaseous diluents may be present.

The temperature at which the reaction may be performed is not critical.Temperatures between about 80 C. and +300 C. have been successfullyemployed. The upper temperature limit is substantially defined by thetemperature at which decomposition of the perfluoroolefin becomesappreciable. Some perfluoroolefin epoxides, particularly the epoxides ofthe perfluoroolefins having a terminal epoxide group, decompose to someextent in the absence of catalysts at temperatures as low as 100 C. Onthe other hand, the epoxides of cyclic perfluoroolefins such asperfluorocyclohexane epoxide and perfluorocyclopentene epoxide aresubstantially more thermally stable than the corresponding open chaincompounds and the rearrangement reaction of this invention may beaccomplished at temperatures exceeding 300 C. Generally speaking, theease with which the rearrangement reaction of this invention tends totake place varies in the same manner as the thermal stability of theparent epoxide, the temperature sensitive epoxides tending to rearrangemore readily than those which are less temperature sensitive.

The time required for the reaction varies with the temperature and withthe nature and amount of catalyst employed, as will be appreciated bythose skilled in the art.

The course of the reaction may be readily determined by observation ofthe characteristic infrared absorption bands due to fluorocarbon atabout 6 to 7 microns, and the characteristic carbonyl absorption bandwhich occurs in the region of 5 to 6 microns. At the high temperatureranges and with more active catalysts, the conversion time may be afraction of a second, and thus such temperatures and catalysts arepreferred for the continuous gas phase conversion of fluoroolefinepoxides to carbonyl compounds by passing the gaseous epoxide over asolid bed of catalyst. In one preferred embodiment of this invention,gamma alumina is employed as the catalyst at a temperature of between C.and 200 C. for the continuous gas phase conversion of perfluoroolefinepoxides to isomeric carbonyl compounds. If it is desired to manufacturehigher molecular weight carbonyl compounds or if it is desired tomanufacture small quantities of carbonyl compounds using a batchprocess, the preferred mode of operation is to contact the fluoroolefinepoxide with the catalyst in solution at temperatures below 100 C.

The reaction of the present invention is an isomerization reaction, and,hence, according to general chemical principles, the pressure at whichit is conducted should be of little significance. This is indeedverified by experience for it has been found that pressures of 4000atmospheres or more may be employed on the one hand, and on the otherhand that the reaction may be successfully performed at pressures orpartial pressures below atmospheric. The highest pressures, however, areless desirable in that they are inconvenient to employ and may tend topromote side reactions thereby detracting from the yield of the desiredproduct.

The process of the present invention is useful for the synthesis of awide variety of fluorocarbon carbonyl compounds which are of greatvalue. Fluorocarbon ketones exhibit many of the properties ofhydrocarbon ketones in undergoing condensation reactions and the like,thereby providing extremely valuable intermediates for the production offluorocarbon compounds. In addition, the ketone groups of fiuoroketonesreadily add water, alcohols, and other hydroxylic compounds to yield gemdiols, acetals, and the like. It has recently been discovered that thehydrates of many of the ketones embraced as products of the process ofthis invention are useful as solvents, plasticizers, and the like formany polymeric materials, particularly those containinghydrogen-bendable groups, such as polyamides, acetal resins, and thelike.

The acid fluorides wherein the carbonyl group is formed at the terminalcarbon atom of the fluorocarbon are likewise valuable intermediates fromwhich acids, esters, amides, and the like containing fluorinesubstituents may be prepared, many of which derivatives are useful assurface-active agents.

The products of the rearrangement reaction may be isolated by a varietyof chemical and physical techniques which are known to those skilled inthe art.

Distillation may be employed to separate the fluorocarbon materials fromthe catalysts and solvent, but, in general, this technique has littleutility in separating the isomeric products themselves since thedifierence in boiling point is generally small.

Gas chromatography is an excellent technique for the separation of smallquantities of fluoro organic isomers of an extremely high degree ofpurity; however, this technique is relatively difiicult to apply whenlarge quantities of material are involved.

When ketones are to be recovered from mixtures of perfluoroolefins andperfluoroolefin epoxides, the ketones may be converted to the hydrateswhich are then readily isolated, and, thereafter, the hydrates may bereconverted to the ketone by the application of strong dehydratingagents such as phosphorus pentoxide.

In the case of acid fluorides, recovery may be effected by conversion toa derivative such as an ester by reacting the acid fluoride with analcohol, to an acid amide by reaction with ammonia or an amine, or tothe acid by reaction with water.

Many other modifications of this invention will occur to those skilledin the art.

The invention is further demonstrated by the following examples whichare intended, however, by way of illustration only and should not beconstrued to limit the scope of this discovery.

EXAMPLE 1 Vapor phase conversion of hcxafluoropropylene epoxide thexafluoroacetone A l-inch internal diameter, hard glass reaction tubewas packed with a 4-inch bed of inch alumina spheres (Alcoa H-15l,manufactured by the Aluminum Company of America, Pittsburgh, Pa.)supported by a layer of 6 mm. quartz rings. The temperature. of thereaction bed was determined by a thermocouple in a well embedded in thecatalyst. The alumina bed was heated to 100 C. and hexafiuoropropyleneepoxide was passed in at the rate of 14 grams/hour concurrently withnitrogen as a carrier gas at the rate of 30 ml./minute. The reaction washalted when to 7 grams of hexafiuoropropylene epoxide had been passed.The volatile product of thi reaction was collected in a trap immersed ina bath of acetone and solid carbon dioxide. The weight of this productwas 2.8 grams, 49% of the theoretical yield. The product was identifiedas hexafluoroacetone by the appearance of major bands in the infraredspectrum at 5.51 microns (medium); 7.44 microns (strong); 8.20 microns(strong); 10.29 microns (strong); 12.83 microns (weak); and 13.95microns (strong). Further identification was made by observation of themass spectral pattern of the gas. The purity (99%) of the product wasestablished by gas chromatographic analysis.

EXAMPLE 2 An alumina column that had previously been used for thesynthesis of hexafiuoroacetone, as in Example 1, was regenerated byheating to 450 C. in a nitrogen stream for one hour. The column was thencooled to 151 C. A total of 30.6 grams of a mixture of hexafiuoroacetoneand hexafluoropropylene epoxide, containing 8 to 9 mole percent ofhexafluoropropylene, was passed through the alumina bed during a periodof approximately two hours. There was collected in the cold trap 26.3grams (83%) of hexafiuoroacetone containing 8 to 9 mole percent ofhexafiuoropropylene. The material. was analyzed by infrared and massspectrometry. There was no hexafluoropropylene epoxide in the product.

EXAMPLE 3 The apparatus of Example 1 was charged with 50 ml. (40.8grams) of gamma alumina catalyst which had been previously used forhexafluoroacetone synthesis as in Example 1 and was heated at 450 C. forone hour in a stream of nitrogen. The catalyst bed was allowed to coolto 79 C. Hexafiuoropropylene epoxide containing 8 to 9 mole percent ofhexafluoropropylene was passed over the catalyst bed at the rate of 10grams/hour along with a slow stream of nitrogen (25 mL/minute) for 123minutes. There was obtained 20.2 grams (90%) of volatile product whichwas identified by mass spectral analysis as being hexafiuoroacetonecontaining 8 to 9 mole percent of hexafiuoropropylene.

EXAMPLE 4 Conversion of hexaflzroropropylene epoxide tohexafluoroacetone in solution A solution of 85 grams ofhexafiuoropropylene epoxide in 50 ml. of liquid sulfur dioxide wastreated with 5.0 grams of aluminum chloride in a stainless steelcylinder. After standing for three days at room temperature, all of theepoxide had been consumed, as determined by infrared spectral analysis.Distillation of the reaction mix- 6 ture yielded 14.9 grams, boilingpoint -45 to ---30 C., of a mixture of pentafiuoropropionyl fluoride andhexafiuoroacetone and 67.0 grams (79% boiling point 30 C., ofhexafluoroacetone with a trace of-pentafluoropropionyl fluoride. Theproducts were identified by comparison of their infrared spectra withthose of authentic samples.

EXAMPLES 5 TO 8 Manufacture of perfluorocyclopentanonePerfluorocycl-opentene, made from commercially availablehexafluorodichlorocyclopentene by fiuorination with potassium fluoridein the presence of N-rnethyl pyrrolidone, was converted to the epoxideby the following process.

2.28 moles of perfluorocyclopentene was mixed with 515 grams of 30%w./v. hydrogen peroxide (4.56 moles H 0 and 250 ml. of reagent grademethanol. The mixture was cooled to 15 C. 1450 ml. of a 25% w./v.solution of potassium hydroxide in methanol was added dropwise to themixture of perfluorocyclopentene and hydrogen peroxide over a period ofabout six hours, maintaining the temperature below -10 C. andmaintaining the pH at a value in the range between pH 8 and pH 10. Thecrude organic product of this process weighed 208 grams. This wasseparated by distillation into two fractions, the larger of which, 83.5%of the total, was shown by infrared analysis to contain 70% of thedesired epoxide and 30% of unreacted perfiuorocyclopentene. The smallerfraction (14.5% of the crude) consisted of substantially pure l-methoxyperfiuorocyclopentene.

The mixture of perfluorocyclopentene and perfiuorocyclopentene epoxidewas then separated by dissolving the mixture in 50 ml. ofdichlorofiuoromethane, refluxing the solution (boiling point of CCl F=-29 C.); then slowly bubbling chlorine into the solution whileirradiating the vessel with an ultraviolet lamp. The progress of theadditive reaction of chlorine to the perfiuorocyclopentene could bereadily followed by observing the rate of decolorization of the solutionwhen the flow of chlorine was interrupted. When the chlorination wascomplete, distillation of the product yielded 131.6 grams ofperfluorocyclopentene epoxide, boiling point 265 C. (Fluorine byelemental analysis 67.5 and 67.3%Calc. for C F O, 66.7%.) The infraredspectrum showed a strong band at 6.55 microns characteristic of theepoxide ring. The nuclear magnetic resonance spectrum was consistentwith perfiuorocyclopentene epoxide exclusively in the chairconformation.

Small samples of the perfiuorocyclopentene epoxide prepared above wereweighed into platinum tubes together with a weighed amount of catalyst.The tubes were crimped to seal the contents, then the tubes were placed\in a pressure vessel and-pressurized to about 500 atmospheres. Thepressure vessel was heated to C. and the temperature raised to 300 C.over 1 /2 hours. The temperature was then held at about 300 C. for afurther two hours. The vessel was then cooled, the pressure released andthe contents of the platinum tubes removed and analyzed. The results ofthese experiments are shown in Table I.

The perfluorocyclopentanone produced by these reacions was characterizedby its infrared and nuclear esonance spectra.

8 hereinabove were placed in a steel shaker vessel, pressured withnitrogen and heated to the desired temperature for the desired period oftime. The assembly was then cooled and the nitrogen pressure released.The

EXAMPLE 9 TO 60 sealed platinum tube was then cooled to liquid nitrogentemperature. The platinum tube was cut open while the The followingexamples illustrate the effect of Venous contents-were frozen, rapidlyconnected to the vacuum atalysts in the rearrangement ofhexafluoropropylene manifold and evacuated. The contents were then d s-P In these examples, two methods e charged by distillation and examinedby infrared analysis. loyed t0 eohtaet the hexaflllefepfepylehe With theMethod B.In this method, the platinum tubes were elected catalyst:replaced with glass Carius tubes. The Carius tubes were Met/1 d A.- h ra i these eXperlmehts W carefully dried and loaded with solvent andcatalyst in Ohdueted in Small Platinum tubes of inch 1/2 lnch a dry box,then attached to a vacuum manifold and filled 1 di m r nd about 7 t0 8inches in length Lehths with the predetermined charge ofhexaflnoropropylene f the tubing Were heated to a cherry red heat toremove epoxide as in the case of the platinum tubes. The conp and sealeda one d T he tubes so P tents of the tube were frozen in liquid nitrogenand the ared were stored in an oven until used. glass tube sealed. Thetubes were then loaded in a steel and Solid catalysts and diluents usd1n thIS Work haker tube and the pressure and temperature slo vly inlel'eStored in a y box with a nitrogen atmosphere creased simultaneously inorder to maintain a pressure Catalyst, Solvent diluent, if p y WereCharged outside the tubes roughly equal to the pressure of the lte thePlatinum tube in this The tube Was then contents in order to preventexplosion or implosion of lOSed With a Piece of clamped Tuhhel tubingand trailsthe glass tube. After heating for the predetermined iffed fromthe y box to a manifold Y The period, the pressure and temperature werethen simulatinum v s l s then Cooled liquid nitrogen taneouslydecreased. The tubes were removed, frozen, erature and evacuated.Hexafiuoropropylene epoxide cut open, sealed to a vacuum line and thecontents reas condensed in a graduated glass tube attached to the mo d ad analyzed, ianifold and cooled in solidified carbon dioxide/acetone, Thresults of these experiments are recorded in the nd the weight ofhexafluoropropylene epoxide det raccompanying Table II. In this table,the starting mateiined assuming a density of 1.7 grarn/ cc. at -78 C. Thrial was a mixture of hexafluoropropylene epoxide and exafiuoropropyleneepoxide was then distilled from the hexafiuoropropylene, the content ofthe epoxide being lass measuring tube into the platinum tube. recordedin weight percent in the appropriate column If gaseous catalysts wereemployed, these were transof Table II. :rred to the reaction vesselusing the vacuum manifold In the experiments carried out at roomtemperature stem and the graduated glass tube in the same manner andbelow, and at autogenous pressure, instead of heat- 5 thehexafiuoropropylene epoxide. ing the tubes in a shaker tube, they wereplaced in a With continued cooling to liquid nitrogen temperature,constant temperature bath. Suitable baths were ice 1e platinum tube wascrimped for a length of 1% inches water (0 C.), refluxing liquid S0 (10C.), and sing a pair of needle-nose pliers, then a cut made acrossrefluxing methyl chloride (24 C.). In some experi- 1e crimped sectionwith an oxygen-gas torch. The tubes ments, the low temperature wasmaintained within a fairly charged were stored in solid carbon dioxideprior to narrow range of values by storing the tubes in a beakerxperimentation. of perchloroethylene kept in the freezer compartment Oneor more of the platinum tubes, loaded as described of a refrigerator.

TABLE II Starting Material: Weight Percent Hexafluoropropylene EpoxideWeightot Volume Tempera- Pressure Time Ex. Method in Hexatluoro-Catalyst Catalyst Solvent of Solvent ture( C.) (atnn) (hrs) Resultspropene (grams) (1111.)

Per- Wt. in

cent grams 10 Dimethyl- 250 25 -l 16 Product mainly forma- CFaCFzCOF.mide. 88 0.15 None 250 55 4 Same hexafiuoroacetone rme 99.4 0.1 Ether 1100 2,000 4 CFQCOCFK, CF3CF2COF and epoxide in -2/l/1 ratio.

88 0.1 100 38 4 5.0 gram material mainly CFaCOCFa.

88 0.1 200 37 4 CFQCOCFJ major product.

88 0.1 250 41 4 OF3COCF3 major product.

99.4 1 .do 150 160 4 Complete reaction.

CF3CF2COF major product.

99.4 5.2 Dimethylaniline. 0 15 do.. 100 160 2 Small amount of red gum.

Major product was CFsCFzCOF.

99.4 5 .do 0.15 do 150 174 2 4.7 gram CFaCFgCOF,

black gum residue.

99.4 12 do -0.1 Ether 1 2,000 4 All of epoxide converted to acidfluorides, CFaCFZCOF present.

A 99.4 12 do -0.1 do 1 25 2,000 16 Small amount or CFsCFBCOF. I A.. 99.413.4 Dimethyl- -0. 15 None 2,000 2 Most of epoxide rearrangedform-amide. to CFgCFzCOF. B 99.4 5 Triethylarnine 0.1 Ether 1 197 4 Fewdrops of water-soluble red oil CFQCF COF. B.- 99.4 4.9 CuO 0.2 None 140107 4 Trace oromcmcon.

TABLE II-Contiuued Starting Material: Weight Percent HexafluoropropyleneEpoxide Weight of Volume Tempera- Pressure Time Ex. Method inHexafluoro- Catalyst Catalyst Solvent of Solvent ture C.) (atm.) (hrs)Results propene (grams) (ml.)

Per- Wt. in cent grams 23.-- B 99.4 4. 7 A1 0.2 140 161 4 OF3COCF3 majorproduct and trace of acid fluoride.

24 B 99. 4 5. PhD; 0.2 do 140 187 4 Trace of acid fluoride (CFaCFzCOF).

25--- B 99. 4 5. 5 CsF 0.2 --.do 140 187 4 Small amount of acid fluoride(CFsOFzCOF).

26.-- B 99. 4 5.1 PF 1 63 140 173 4 Very small amounts of CFsCOCFg acidfluoride (CFQCFZCOF).

27-.- B 99. 4 5 SF 1 54 140 170 4 Very small amounts of 28.- B 99. 4 5BF; etherate 0. 4 --do 140 170 4 Trace acid fluoride (OF3OF2COF).

29 B 99. 4 5 FeCl; 0.2 .....do 140 170 4 Major product CFgCOCFz,

trace acid fluoride (CFaCFzCOF).

30-- B 99. 4 5 V001 0.2 -do 140 170 2 Major product CF COCF 31.-- B 99.44.9 T1014 0.2 do 140 166 2 Small amount of CFaCOCFa.

32--- B 99.4 5.3 Pyridine-N-oxide. 0.2 do 140 180 2 Small amount of 33--B 99. 4 5 Hexamethylene 0. 1 Ether 1 100 178 4 Almost quantitativecontetramine. version to OF3CF2CO F.

34 B 99. 4 5 do 0. 1 do 1 4 High conversion to CFaCFzCOF.

35.-- A 99.4 12 -do 0.1 do 1 50 4,000 4 Some CFQCFZCOF.

36- B 99. 4 5. 1 Tetramethyl- 0. 15 None 140 173 4 0.5 gram ofnitrogenous guam'dine. liquid: high conversion to CFaCFzCOF.

37- B 99. 4 5. 2 Tetrakis(diethy1- 0. 15 --do 140 176 4 Water-solublered tar, 5.1

amino)ethylene. gram CFaCFeCOF.

38. A 99. 4 12 Pyridine 0. 1 Ether 1 4, 000 0.3 gram water-soluble blackoil, remainder CFgOFgCOF.

39- A 99. 4 12 Reduced iron 0. 5 N one 4, 000 4 Large amount of oxide.CFzCFzCOF, lesser amounts of CF C 0 CFsand other fluorine compounds.

40. A 99. 4 12 Reduced cobalt 0. 5 -do. 100 4, 000 4 Major product CFCOCF oxide. some acid fluorides mainly( CF3CF2COF).

41 A 99. 4 12 Reduced C; 1. 5 do 4, 000 4 Small amount on Charcoal.CFaCFCzOF, decomp.

products.

42- A 99.4 12 .do 1. 5 .do 100 4, 000 4 0.3 gram oil, remainder ofepoxide converted to CFaCFzCOF.

43- A 99. 4 12 Lower valent 1. 5 do 140 4, 000 4 1.8 gram liquidproduct, re-

tungsteu oxide mainder CFaCFzCOF. on charcoal.

44- A 99. 4 12 Reduced onium 1. 5 do. 140 4, 000 4 0.9 gram liquid,remainder 0X59 on char- CFaCFzGOF. V 7 co 45. A 99. 4 12 do 1. 5 100 4,000 4 0.3 gram liquid, remainder CFaCFeC OF.

46 A 99. 4 12 Chromium oxide 1 100 4, 000 4 Mostly hexafluoroacetone,

on alumina, 0: some acid fluoride. pyrolyzed.

47. A 99. 4 12 W0; on 11110;".-. 1. 5 do. 100 4, 000 4 Completeconversion to CF30 0 CFz-l-acid fluorides (mainly CFaCFzCOF).

48--- A 99.4 12 M003 on AlrO 1. 5 do 100 4,000 4 CFttCOCFa principalprod- 49 A 99. 4 12 W(CO)r 0.5 do 100 4, 000 4 Small amount of 50. A 99.4 12 Fe(C0)5 0. 3 do- 100 4, 000 4 Major conversion to CF CO C1 51. A99. 4 12 W0: 1 .do 100 4, 000 4 Major conversion to CF3COCF3, some acidfluorides (mainly CF3CF2COF).

52. A 99. 4 7 T101 on A1103"--- 1 -do- 100 4, 000 4 Major product wasCF30 O CFa.

53- A 99. 4 7 Reduced CrO; on 0. 5 do 100 4, 000 4 Nearly quantitativeeon- 99. 4 7 silica-alumina. version to hexafluoroacetone.

54 A 99.4 7 Ni Molybdite 1. 1 do 100 4, 000 4 CFBCOCFB produced.

55--- A 99. 4 7 Bauxite (dried) 0. 5 -do. 25 48 Small amount of 0 F 0 OC F3 and CFaCFZCOF 56 A 99. 4 7 'lrimethylamine 0. 053 do 15 48 0.2 gramdimer 1.5 gram CF3CF2C OF.

57 An... 99. 4 7 Triethylamine 0.1 Ether 2 5 to 15 5 4 5.4 gramCF3CF2COF.

' 99. 4 7 o 0. 1 Tetrahydro- 2 -5 to 15 a 4 3.4 gram CFaCFzCOF.

uran.

59--- A 99. 4 7 Pyridine 0.1 Ether 2 -5 to 15 3 4 2.4 gram CFsCFzCOF.

60--- A 99. 4 7 Dimeghylform- O. 1 Tetrahydro- 2 -5 to l5 3 4 3.1 gramCFzCFaCOF.

ann e. uran.

l Milligrams.

5 Days.

1 1 EXAMPLE 61 Rearrangement f 0mega-hydroperflaoroheptene-I-ep0xide toomega-hydroperfluoroheptanoyl fluoride A 3-grarn sample ofomega-hydroperfluoroheptene-1 :poxide was placed in a glass Carius tube.The tube was :ooled to 80 C. and evacuated. There was then in- .roduced0.5 gram of trimethylamine and the tube was ;ealed. After heating to 50C. for two hours, the ube was opened and 1.8 gram (60%) of omega-hydro-Jerfluoroheptanoyl fluoride, boiling point 88 to 91 C., was isolated.

EXAMPLE 62 Rearrangement of omega-hydroperfluoroheptene-I-epoxide to7-hydroperflu0ro-2-heptanone The procedure of Example 61 is repeatedusing 0.2 gram of ferric chloride instead of trimethyl amine and aemperature of 135 C. There are isolated 7-hydroperiuoro-2-heptanone,boiling point 87 to 89 C., in 50% ield together with trace amounts ofomega-hydrohepanoyl fluoride.

EXAMPLE 63 Rearrangement of tetrafluoroethylene epoxide t0perfluoroacetyl fluoride EXAMPLE 64 Rearrangement ofperfluoroisobutylene oxide to perfluoroisobutyryl fluoride To a 50 m1.Carius tube containing- 0.6 gram of Darco 2 x 20 charcoal, previouslydried at 400 C., was added .6 grams of perfluoroisobutylene oxide,boiling point 0 to C. The tube was sealed and kept at 0 to 25 C. for 8hours. There was recovered by distillation 5.2 gram of mixture ofperfluoroisobutyryl fluoride, boiling point 3 to 1 C., and a second acidfluoride of boiling oint 43 to 44 C. The perfluoroisobutyryl fluoridewas hown by gas chromatography to constitute 25 to 35% of 1e mixture. Apure sample exhibited NMR and IR pectra identical to those of anauthentic sample prepared y reaction of carbonyl fluoride withhexafluoropropylene atalyzed by potassium fluoride. The second acidfluoride 'as shown to have the structure CF CF( CF CF OC (CF 3 CFOEXAMPLES 65-68 Preparation of perfluorocyclohexanonePerfluorocyclohexene, prepared by the fluorination of ither1,2-dichloroperfluorocyclohexene-1 or 1,2,4,4,5,5-exachloro-3,3,6,6-tetrafluorocyclohexene-1 with potassim fluoride in thepresence of N-methylpyrrolidone, was Jnverted to the epoxide as follows.

A mixture of 52.4 grams (0.20 mol) of perfluorocycloexene, 50 ml. ofabsolute methanol and 35 ml. (ca. .3 mol) of 30% hydrogen peroxide wascooled to -15 130 ml. of a 20% solution of potassium hydroxide [methanolwas added dropwise over a three hour period taintaining the temperaturebetween -15 and -25 C. 1d the pH within the range 8 to 10. At the end ofthis me a sample of the crude organic product showed no nsaturation at.7 to 5.8 rnicrons in the infrared buta rong epoxide band at 6.7microns. The volatile products ere removed by distillation under 25 to30 mm. pressure. he lower fluorocarbon layer was separated and fraction-12 ally distilled to give 28.8 grams (52%) of perfluorocyclohexeneepoxide; RP. 53 to 55.

Analysis.-Calcd for C F O: percent C, 25.9; percent F, 68.3. Found:percent C, 25.5, 25.7; percent F, 68.1, 68.0.

Samples of the perfluorocyclohexene epoxide prepared above were placedin sealed glass tubes with cesium fluoride as the catalyst and heated atdilferent temperatures for two hours. The tubes were cooled and thecontents analyzed by infrared analysis. The results of these runs areshown in Table III. The ketone was identified by infrared spectra andelemental analysis.

TABLE III Weight of Ex. Perfluoro- Wt. Cesium Tem- Results cyclohexeneFluoride, g. perature, Epoxide, g. C.

65 1. 55 0.003 300 0.7 g. pure perfluorocyclohexanone. 66.- 1. 66 0. 003200 0.9 g. product 50% ketone. 67...- 1. 64 0.003 250 0.85 g. pureperfluorocyclohexanone. 68.... 26.8 2. 3 1 300 10.7 g. redistilledperfluorocyclohexanone, B.P. 54 to 56.

1 Heated in a 320 ml. Hastelloy bomb for three hours.

We claim:

1. A method for making fluorinated carbonyl compounds which comprisescontacting a compound having the chemical formula wherein R R and R areradicals selected from the class consisting of fluorine radicals,perfluoroalkyl radicals having from 1 to 8 carbon atoms,omega-hydroperfluoroalkyl radicals having from 1 to 8 carbon atoms and,pairwise, perfluoroalkylene biradicals having from 2 to 8 carbon atoms,with a catalytic amount of an alkali metal fluoride and thereafterrecovering a fluorinated carbonyl compound from the reaction product.

2. Process of manufacturing perfluorocyclopentanone which comprisescontacting perfluorocyclopentene epoxide with a catalytic amount of analkali metal fluoride and recovering perfluorocyclopentanone from thereaction product.

3. Process of manufacturing perfluorocyclohexanone which comprisescontacting perfluorocyclohexene epoxide with a catalytic amount of analkali metal fluoride and recovering perfluorocyclohexanone from thereaction product.

4. Process of manufacturing said fluorides having the composition R CFCOF wherein R is a per-fluoroalkyl radical having from 1 to 8 carbonatoms which comprises contacting a l-fluoroolefin epoxide having theformula R;C C F: with a catalytic amount of an alkali metal fluoride andthereafter recovering an acid fluoride from the reaction product.

5. Process of claim 4 wherein the said l-fluoroolefin epoxide ishexafluoropropylene epoxide.

6. Process of making fluorinated ketones having the formula R COCFwherein R is selected from the class consisting of perfluoroalkylradicals having from 1 to 8 carbon atoms and omega-hydroperfluoroalkylradicals having from 1 to 8 carbons, which comprises contacting acompound having the formula is hexafluoropropylene epoxide.

'9. The method of making fiuoroketones having the chemical formula RCOCF wherein R is selected from the class consisting of perfluoroalkylradicals having from 1 to 8 carbon atoms and omega-hydroperfluoroalkylradicals having from 1 to 8 carbon atoms which comprises passing thevapor of a fluoroepoxide having the formula Rr-CF-CFg over gamma-aluminaat a temperature in the range between 100 C. and 200 C., and thereafterrecovering a fluoroketone from the reaction product.

10. Method of claim 9 in which the compound having the chemical formulaRf (l 0 F2 is hexafluoropropylene epoxide.

References Cited by the Examiner UNITED STATES PATENTS 1,976,265 11/1934Mugdan et al 260544 2,456,768 12/1948 Chaney 260544 X 2,799,708 7/1957Oakley et a1 260586 X 3,009,959 11/1961 Heath et al 260586 X 3,151,1679/1964 Eisenmann et al. 260586 3,213,134 11/1965 Morin 260544 OTHERREFERENCES Wethington et al., Chem. Abstracts, vol. 54 (1960), p.23674e.

McBee et al., J. Am. Chem. Soc., vol. 78, pp. 3851- 3854 (1956).

LORRAINE A. WEINBERGER, Primary Examiner.

R. K. JACKSON, Examiner.

1. A METHOD FOR MAKING FLUORINATED CARBONYL COMPOUNDS WHICH COMPRISESCONTACTING A COMPOUND HAVING THE CHEMICAL FORMULA